Cannot change in-game brightness

Just installed the new 0.98 version and I am unable to change the brightness at all.

Moving the slider up or down in the menu video settings makes no difference. The game is still very much playable, but everything is dark-ish and glossy looking due to the reduced gamma. Any ideas?

That's a strange thing to say. I haven't had to set this option for a long time and my game isn't any darker than usual. Did you look in the config file? (mods/SSHIP_098/configuration.cfg)
If you can't find a solution through play, you can increase your screen brightness :hmm:

Contents of my root file medieval2.preference.cfg (in the Medieval2totalwar folder):

Spoiler Alert, click show to read: 

[video]
anisotropic_level = 16
anti_alias_mode = off
antialiasing = 8
assassination_movies = 0
autodetect = 0
battle_resolution = 1920 1200
bloom = 0
building_detail = high
campaign_resolution = 1920 1200
depth_shadows = 2
depth_shadows_resolution = 3
effect_quality = highest
event_movies = 1
gamma = 128
grass_distance = 500
ground_buffers_per_node = 4
ground_cover_buffers_per_node = 4
infiltration_movies = 0
model_buffers_per_node = 4
no_background_fmv = 1
reflection = 1
sabotage_movies = 0
shader = 2
show_banners = 0
show_package_litter = 1
skip_mip_levels = 0
splashes = 1
sprite_buffers_per_node = 4
stencil_shadows = 1
subtitles = 0
terrain_quality = custom
texture_filtering = 2
unit_detail = higher
vegetation = 1
vegetation_quality = high
vsync = 1
water_buffers_per_node = 4
widescreen = 1